140 NAMES AND PROPOSITIONS. 



and the differences which are not of kind ; they meant to inti- 

 mate that genera and species must be Kinds. Their notion 

 of the essence of a thing was a vague notion of a something 

 which makes it what it is, i. e. which makes it the Kind of 

 thing that it is which causes it to have all that variety of 

 properties which distinguish its Kind. But when the matter 

 came to be looked at more closely, nobody could discover what 

 caused the thing to have all those properties, nor even that 

 there was anything which caused it to have them. Logicians, 

 however, not liking to admit this, and being unable to detect 

 what made the thing to be what it was, satisfied themselves 

 with what made it to be what it was called. Of the innu- 

 merable properties, known and unknown, that are common to 

 the class man, a portion only, and of course a very small 

 portion, are connoted by its name ; these few, however, will 

 naturally have been thus distinguished from the rest either for 

 their greater obviousness, or for greater supposed importance. 

 These properties, then, which were connoted by the name, 

 logicians seized upon, and called them the essence of the 

 species; and not stopping there, they affirmed them, in the 

 case of the infima species, to be the essence of the individual 

 too j for it was their maxim, that the species contained the 

 " whole essence" of the thing. Metaphysics, that fertile field 

 of delusion propagated by language, does not afford a more 

 signal instance of such delusion. On this account it was that 

 rationality, being connoted by the name man, was allowed to 

 be a differentia of the class ; but the peculiarity of cooking 

 their food, not being connoted, was relegated to the class of 

 accidental properties. 



The distinction, therefore, between Differentia, Proprium, 

 and Accidens, is not grounded in the nature of things, but in 

 the connotation of names ; and we must seek it there, if we 

 wish to find what it is. 



From the fact that the genus includes the species, in other 

 words denotes more than the species, or is predicable of a 

 greater number of individuals, it follows that the species must 

 connote more than the genus. It must connote all the attri- 

 butes which the genus connotes, or there would be nothing 



